More on Fermented Cod Liver Oil (An Interview with the Boss and Readers’ Best Swallow Tips)

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image I love it when a plan comes together.

Questions asked, questions answered. It’s a beautiful thing.

I was very pleased to bring your questions (plus mine) to Dave Wetzel, owner of Green Pasture Products, where they make the only fermented cod liver oil this side of the 17th century. (My words, not his.) Be sure to check out my first post detailing our family’s experiences with fermented cod liver oil.

After the interview, I list readers’ best tips for getting the cod liver oil down without tasting it quite so much, so be sure to scroll down to the bottom of the post to read them!


The Interview: Fermented Cod Liver Oil

Many, many people wanted to know what the difference was between the regular cod liver oil that used to be recommended by the Weston A. Price Foundation and the fermented, which is more expensive. What makes fermented cod liver oil have more health benefits? I tried my best to understand the whys and wherefores of this for you! (Note: As of 18 months ago, the WAPF still had a few non-fermented cod liver oils on their “good” list, but fermented CLO is the only kind on the “best” list. Don’t be confused: even though there are multiple sources listed for FCLO, Green Pasture is the only company that produces it. It’s all from Dave!)

new gravatar 125 Kitchen Stewardship: Why fermented? What is the process you use, and how do you know it’s “traditional?”

green pasture large Dave Wetzel/Green Pasture: Throughout history we’ve always consumed fermented products from sea – in biblical times, in the book of Tobias , the archangel told Tobias to save organs pulled from the sea to make good medicine. In Roman times, the viscera – all the fish guts, everything you’re not using to eat – was put in a drum and fermented. On the bottom was gum, and everybody got that, even peasants, while the Roman soldiers got the oil from top. They often credited their strength to it.

Cod liver oil was always fermented until 1850, when we learned to render. If heated, we could extract oil in day instead of fermenting which takes 6 months. They didn’t understand oxidation and that they were cheating the system, so as we started to industrialize fish oils, we lost a lot of the nutrition. I suspect the product wasn’t as effective, but we have no samples so it’s just a guess. Likely this heated oil would oxidize very quickly. When you heat the viscera, you break bonds and create free radicals which causes oxidation.

Around the turn of century, cod liver oil started to lose favor. The industry used heat and pressure, and they found that nitrogen would clean up the free radicals. Unfortunately, this tasteless, colorless product was also probably nutrient less. It was all about marketability.

Making fermented cod liver oil is taking it back to its historical roots. Throughout history FCLO was commonly used, and people knew what it did and that it was important without understanding nutrients. I don’t think regular cod liver oil is even the same product that was revered for centuries.

KS: What is the purpose of fermentation? How does it increase nutrition?

GP: The purpose of fermentation is to introduce bacterial and enzymatic action that breaks down the liver.

As far as how much nutrition, why bother testing for amounts of vitamin D, because we don’t understand the question. I have a book with 937 structures of vit d – too much to sort through. Vitamin D is a hormone, not even a vitamin, and what we don’t know about it probably outweighs what we do know. We may not know exactly what we need, so we just do it the way it worked for thousands of years.

Note: I always figured that fermentation generally started with a food and finished with that same food, just healthier with probiotics. For example, when I lacto-ferment mayonnaise or salsa, I start with mayo or salsa, add whey, and I finish with mayo or salsa. I thought fermenting cod liver oil was simply starting with cod liver oil, then fermenting it to increase its nutrition and add beneficial bacteria. Not so!

The fermentation is actually the process of extracting the oil from the liver, not just something to do to the oil itself. Green Pasture ferments the cod livers, which brings the oil out of them, thus avoiding heat, pressure, and chemicals processes, all of which could pull the oil out of the livers, but in an unnatural and unhealthy way. It’s about methodology, not boosting nutrition.

Fermented cod liver oil is more like yogurt – you start with milk, add bacteria, and you end up with yogurt. I’m sure the food industry could figure out how to thicken up milk and then give it a tang like yogurt, and it would be as close to yogurt’s nutritional profile as processed American cheese slices are to sharp cheddar. The processing being different makes a different product. Good, healthy oils are always processed at a low temp and then not altered. Why are the other brands adding synthetic vitamins? The fermentation really does seem like the most natural way to extract oil from fish livers.

KS: How do we know how much to take? What is the proper dose?

GP: Dosage is the wording for a drug – we’re used to drug terms, but this isn’t a drug. Think of it as a FOOD vs. a drug. Typically most people find 1/8-1/2 teaspoon beneficial, something less than a teaspoon. Some people do much better on skate oil; most people do better with butter oil included. Certain people are going for certain aims, and need a bigger dose, and within a week if they don’t have enough they fall apart. A typical person needs a smaller dose.

KS:What do people notice before and after taking fermented cod liver oil? [I get lost when folks start talking about understanding the right amount to use/take/eat by watching their own body. What am I supposed to look for? I’m not always that observant!]

GP: The FDA won’t actually allow Green Pasture to make health claims.

Well. Here are things I (Katie) have heard people say when they take FCLO:

You look for:

  • How do you know your immune system is working properly? You stay healthy. If getting a cold is a bad thing, then you know the system is working when you start feeling a cold coming on, and it’s gone by the next morning.
  • Some look at hair and skin, things you can see. Healthy, sleek hair and supple skin.
  • Some notice that symptoms of mental distress like anxiety dissipate with large doses of fermented cod liver oil.
  • Some people just go scientific and get their Vitamin D levels tested!
Katie’s thoughts: It’s nearly impossible to say that one thing can keep you from getting sick all the time, though. For example, I used to hold up our family’s very healthy winter as an example of the power of real food: chicken stock, coconut oil, butter. I thought because we were eating so much healthier that firs winter on a traditional diet, that we were responsible for our good health. This fall, if anything, we should be even healthier diet-wise, and we’ve added FCLO and elderberry syrup more or less regularly…and the kids have been sick for about six weeks. ??? I haven’t caught a thing, but I now think I’m just dumb lucky and not responsible at all!My point is that it’s pretty hard to say “I would have gotten a cold for sure if I didn’t ____” or “My cold was much shorter than it would have been had I not been eating ___.” You know what I mean? That’s why there are scientific studies. As much as I appreciate anecdotal evidence, I don’t know that it works for this one.

KS: What’s the youngest age to give fermented cod liver oil?

GP: I’d like to think that a breastfeeding mom provides everything baby needs. Taking FCLO while breastfeeding is still a good idea though. I have six kids, and with my youngest, we put some on his bottom when changing the diaper so it absorbs through the skin. Green Pasture is going to come out with some skin creams and different dermatological applications for CLO. There’s no reason why you can’t give to young baby, since it’s a food, not a drug, if you feel you need it. (Note: it might be worth checking with your pediatrician, since many of them recommend a vitamin supplement for breastfed babies to get their vitamin D. Better to use real food!)

My discipline for children five years old and over works really well: if they grumble they get a second dose. That doesn’t last more than two weeks!

KS: Can you overdose on cod liver oil?

GP: Some doctors prescribe larger amounts for people; it’s a food, it’s the whole form. Overdosing may not be the correct term.

I would suspect one would become sick from too much OIL rather than CLO. Vitamin D toxicity from the sun is a sunburn, so that’s very dependent on the person. Perhaps everyone has a different level of Vitamin D that they require. Research is changing so fast; what he hear about Vitamin D right now will not be what we hear 10 years from now. There is so much conflict.

KS: Does CLO take the place of a fish oil supplement?

GP: Why take the fish oil? Fermented cod liver oil is fish oil, just from the liver, not the skin.
From Food Renegade: Should you Take Fish Oil?

Note: I found a really interesting forum online – the facts from the medical doctor of course may or may be real, as the good doctor could be any random person…but there are lots of journal citations, and that always makes me happy. If you want to read more about the health benefits of cod liver oil, this is one possible place to start.
KS:Does fermented cod liver oil spoil?

GP: Our testing indicates it’s very difficult to get a peroxide rating. Fermented cod liver oil is extraordinarily stable. In history they never had refrigeration. The new labels won’t require refrigeration.

Because the process is not industrialized, we do get a wide variety of flavors and odors, and that won’t change as long as we stick with real methods. (Kind of like cooking in your kitchen, sometimes breads work out better than others!)

Note: It’s hard to find sources, at least online, on fermented cod liver oil that aren’t connected to either the Weston A. Price Foundation or Green Pasture. If you want to know more about Green Pasture’s processing techniques, this article (also by Dave) is very detailed and interesting. At the end, there are some other sources, including this one from a family practice physician (DO) in California:

“One of the nutrients found in cod liver oil is vitamin D. I found that it took just 2,800 IU of the vitamin D contained in Green Pasture’s fermented cod liver oil in combination with the butter oil to raise one patient’s serum 25-hydroxy vitamin D level from 12.6 ng/ml to 82.3 ng/ml in just three months. According to the guidelines for supplementing synthetic vitamin D3 it would have taken 7,000 IU to achieve this and without all the benefits of the many other fat-soluble nutrients found in these oils. What a testament to the power of nutrients in their natural form!”

Thanks, Dave! You can order Green Pasture fermented cod liver oil here, or at other retailers under the label “Blue Ice.”

How to Take Fermented Cod Liver Oil

KS readers came through with great suggestions in the comments of Our Experiences with Fermented Cod Liver Oil, and I just have to share them:

  • Mix dose of Oslo Orange into a Tbs or two of orange juice – fishy taste totally hidden!
  • Add raw honey to the chocolate cream – I tried this one, and it’s a radically different experience. I drizzled a big of honey on top of my spoonful of the high vitamin butter blend, turned the spoon over so the honey hit my tongue first, and I’m telling you – it was almost pleasant. That’s a huge upgrade!
  • Mix in with creamy raw milk; the fat helps overwrite the fishy taste.
  • Using a straw when mixing with juice or milk makes a big difference – keeps the nose far enough away from the fishy smell.
  • Use a shot glass and shoot it back!
  • Chase with pickles! My daughter would love this one, and we’re trying it tomorrow. My husband says she looks so excited to take her CLO “like a big girl” and is then utterly betrayed after the taste hits her tongue. I am thinking of video-taping the scene for you guys, just for fun!
  • My new method: take your elderberry syrup immediately after the cod liver oil. Covers it up nicely!
  • Buy the butter oil separately and take together (frugal tip).
  • Order a dozen with friends (frugal tip!) and test flavors to see what your family likes best.
  • Take at night so fishy burps are just in your dreams…

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Disclosure: Green Pasture is an advertiser at KS this month, and this post is their complementary mention. However, readers (and I) also wanted to hear the answers anyway, so that works out great! See my full disclosure statement here.

Photo from The Ancient Brit on Flickr.

Click here for my disclaimer and advertising disclosure - affiliate links in this post will earn commission based on sales, but it doesn't change your price.

20 Bites of Conversation So Far

  1. elaine says

    Very interesting info – thanks for taking the time to interview Dave.

    I also appreciate you sending a note along to him with my frustrations about customer service. He might be interested to know that I have tried to call the company on more than several occasions — never a call back, never a return email. So, as long as he is the only game in town he doesn’t really have to worry to much about it, I guess. Too bad.

    On a more cheerful note – I will say that we tried the Artic Mint (it was on sale last week) and are THRILLED!! Having tried the Regular “flavor” (ha!) (blech) and the Mediterranean (BLECH, BLECH, BLECH) – this is amazing. I can even lick the spoon! I don’t know that I’ll ever try another flavor again :) No more grousing from the kids about taking CLO. Yay!!

    (Sorry, I’m terribly long winded today!) — one quick question about the Butter Oil. I just received my first bottle of it and it’s a solid so I can’t really “pour” it the way I “pour” my CLO — any tips or suggestions?? Right now I’m salting it and eating it off the spoon but that’s pretty gross.

    Thanks so much, Katie! I love your blog and appreciate all of your hard work!!

    • Sarah W says

      Sorry to hear about your experiences with customer service. I’ve only emailed them one time, but I got a response within a day or two (from Dave).

      As for the butter oil, what I do is just stick a clean knife in the jar and spread it on toast or whatever warm thing I might be eating for breakfast, just like I would butter. If it’s toast, I then spread regular butter over it and eat as usual!

      • elaine says

        @Sarah – thanks for the tip! I love real, pastured butter straight off the knife (family thinks I’ve totally lost it!) but the butter oil was a little bit stronger. Off to make a piece of toast :)

  2. Judy says

    thanks for the article. I was also wandering about the butter oil also. I have some that turned gritty and wondering if it is bad now. Do you know how long the butter oil lasts?

  3. says

    Okay, so we’re weird. :)

    We LIKE the FCLO. I’ve been taking the Cinnamon Tingle for a couple weeks now and I actually do like it. No need to worry about how to get it down! My 2-year-old will take a spoonful of the Chocolate Cream and lick it until it’s gone (she gets a small piece of ‘real’ chocolate as a treat, but really, she doesn’t mind). My son won’t take it (16 months) and my husband takes the capsules, when he remembers.

    A couple weeks ago, right when we got it, we were exposed to two bad colds, one on a Friday, the other on the following Tuesday. Some days I felt like a cold was coming on and I’d crave FCLO and take an extra dose. I also took extra elderberry. And we didn’t get sick! I KNOW, based on how I felt, that I would have gotten sick had I not been taking FCLO (previous experience tells me so). It was REALLY helped us. We love it!

  4. says

    Don’t ask me how or why, but my 2 1/2 year old and 10 month old take their FLCO (orange flavor) in their smoothies! I wouldn’t dare drink it but they drink it right up! I plan on adding it to their smoothies until they start complaining (hopefully they won’t?). :)

    • Katie says

      That does seem old…I would recommend emailing Dave at Green Pasture with your question, but only if you’ve got fermented CLO. If it’s another brand, I’d toss it! :) Katie

  5. Liz says

    I can attest to what Dave said about some people needing their FCLO or they “fall apart”. I had run out of FCLO and my next order was taking longer to arrive that I had anticipated. I suffered from headaches, sleep problems, heartburn, and extreme MOODINESS (all of these problems were the norm before taking FCLO) until my order arrived. My husband insists that I never be without it again!

  6. says

    I find that taking the FCLO with enzymes completely eliminates fish burps. I also mix up some coconut oil with the FCLO and use a dropper to put it into capsules. No fishy burps or aftertaste when I do that.

    • Katie G. says

      Oh my goodness, genius! I’m totally trying this out. My mom has a capsuling system, so this should be easy.

      I am pretty good about “taking my medicine”, but I guess I’m not when it’s long term. In the beginning I would just shoot it in my mouth with the syringe and chase it with my egg yolk/veggie juice morning drink (got the taste right out), but it got to the point where the taste would activate my gag reflex and I would nearly vomit at the taste… I know, so melodramatic. So hopefully this will help because I really want to take it and not waste all of the fclo I bought already.

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